In late trading stock market wires were buzzing with stories that a break- up takeover bid was imminent. The shares, at one time down 3p, ended 8p higher at 422p.
In the fiercely competitive but still lucrative world of telephone networks Cable has looked increasingly vulnerable.
It is accepted that the parts of Cable are worth much more than the whole - currently valued by the market at pounds 9.1bn. Sum-of-the-parts valuations are thought to nudge pounds 17bn.
The group has a wide spread of interests including 57.5 per cent of Hongkong Telecom and 80 per cent of Mercury Communications.
A sale of Mercury to possibly the US giant AT&T is a theory that has for long enjoyed a market following. And, with the inevitable takeover of Hong Kong, there is clearly a case for Cable cutting and running from the colony.
But two persistent stories, perhaps unlikely, are showing signs of capturing the imagination. One is a strike from BT, with all the regulatory hurdles it would create; the other is a break-up bid, possibly US-inspired.
If BT, cutting telephone prices to meet Mercury competition, should feel Cable represented a useful element in its campaign for international power, it could sell Hongkong Telecom and Mercury and still make the deal pay by retaining the remaining Cable interests. BT fell 4p to 394.5p.
The rest of the market had an uneventful session, with the FT-SE 100 index up 9.5 points to 3,319.4 in subdued trading.
Hopes of a cut in German interest rates today, a firm New York display and central bank support for the weak US dollar combined to help sentiment.
Pearson, the banking and media group, rose 8p to 606p. Ahead of an analysts' visit to Spain, where Pearson has publishing and theme park interests, Henderson Crosthwaite has produced a buy recommendation. It suspects the Spanish trip will lead to profit upgradings.
Unilever was firm ahead of an investment presentation today and Shell rose 4p to 772p following a meeting with analysts. Bass, which has been meeting analysts, dropped 6p to 583p on rumoured Barclays de Zoete Wedd disenchantment.
Rolls-Royce held at 188p. The aero-engine group is due to meet US and UK analysts next month. Rumours are drifting around of Middle and Far Eastern aircraft deals that would swell the group's order book.
London International, the healthcare group reporting today, held at 107p despite talk it could surprise with figures above the expected pounds 14m.
Eurotunnel remained depressed although the company stressed it would not make a cash call on shareholders this year. But with the shares down 6p at 182p there is little prospect of the hoped-for cash injection from the exercise of warrants.
Kingfisher gained 4p to 457p after its shareholders' meeting, although there was talk of a hovering line of 5 million shares seeking a home. The British Gas confrontation left the shares 3p higher at 302.5p.
MR Data Management had an eventful session, with market-makers prepared to offer only "indicative" prices ahead of a rumoured profit warning. When the warning duly arrived the shares were traded at 55p, down 35p. The group said profits would be around pounds 3.5m; the market had expected pounds 8.5m.
Harrington Kilbride, the publisher, responded to its profit warning with an 8p fall to 31p.
Body Shop, which warned about static profits earlier this month, continued its ragged retreat, down another 4p to 109p. The shares have been 194p this year and in 1992 touched 369p.
The engineer Thomas Locker was busily traded but held at 18p with the non-voting shares at 15.5p. John Carr, a Scot with building and engineering interests, has picked up 21.61 per cent of the votes from descendants of the founder. He paid 15.25p a share. The group recently returned to profits. Mr Carr said the shares were undervalued and he had acquired his stake as an "investment".
Kelsey Industries, the soldering and roof group, gained a further 30.5p to 455p. Since outstanding figures announced on Tuesday the shares have climbed 100p.
Merchant Retail, the department stores and supermarkets group, held at 17.5p. Andrew Perloff, the property man, has increased his interest to 4.4 per cent.
Lionheart, the household goods group, slipped 0.25p to 3.75p with Seaq putting volume at almost 30 million shares. Many of the trades went through at 2.75p. My Kinda Town, a restaurant chain, was another actively traded, with a turnover of 23 million. The price firmed to 9.75p.
Irish buying was said to be responsible for a 3p gain to 67p by Tinsley Robor, the packaging group; Shoprite, the former food discounter now regarded as a shell, rose 0.75p to 7.75p, awaiting results. Before the group's dramatic fall from grace the shares topped 240p.